HAEM5:B-lymphoblastic leukaemia/lymphoma with iAMP21: Difference between revisions

 

==Morphologic Features==

 

 

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!Chr #!!'''Gain, Loss, Amp, LOH'''!!'''Minimal Region Cytoband and/or Genomic Coordinates [Genome Build; Size]'''!!'''Relevant Gene(s)'''

!'''Diagnostic, Prognostic, and Therapeutic Significance - D, P, T'''

!'''Established Clinical Significance Per Guidelines - Yes or No (Source)'''

!'''Clinical Relevance Details/Other Notes'''

!'''Prevalence -'''

'''Common >20%, Recurrent 5-20% or Rare <5% (Disease)'''

!'''Diagnostic, Prognostic, and Therapeutic Significance - D, P, T'''

!'''Established Clinical Significance Per Guidelines - Yes or No (Source)'''

!'''Clinical Relevance Details/Other Notes'''

!Gene!!'''Genetic Alteration'''!!'''Tumor Suppressor Gene, Oncogene, Other'''!!'''Prevalence -'''

'''Common >20%, Recurrent 5-20% or Rare <5% (Disease)'''

!'''Diagnostic, Prognostic, and Therapeutic Significance - D, P, T  '''

!'''Established Clinical Significance Per Guidelines - Yes or No (Source)'''

!'''Clinical Relevance Details/Other Notes'''

!Gene; Genetic Alteration!!'''Presumed Mechanism (Tumor Suppressor Gene [TSG] / Oncogene / Other)'''!!'''Prevalence (COSMIC /  TCGA / Other)'''!!'''Concomitant Mutations'''!!'''Mutually Exclusive Mutations'''

!'''Diagnostic Significance (Yes, No or Unknown)'''

* Intrachromosomal amplification of chromosome 21 (iAMP21) is a neoplasm of lymphoblasts that are of the B-cell lineage. It is characterized by amplification of the ''RUNX1'' gene at 21q22.3 on a structurally abnormal chromosome 21. Amplification is defined as ≥5 copies of ''RUNX1'' detected by FISH or ≥3 copies of ''RUNX1'' on a single abnormal chromosome 21.<ref name=":02" />

* iAMP21 is observed most often in the older pediatric group (median age of 9 years, with a range of 2-30 years). It accounts for ~2% of B-ALL cases including ~2% of standard-risk and 3% of high-risk patients. The incidence in adult B-ALL has not been established; however, it appears to be less prevalent than in the pediatric population.<ref name=":0" />

* Further, patients carrying a rob(15;21)(q10;q10) have an ~2700-fold increased risk of developing iAMP21 ALL compared to the general population. Additionally, patients with a constitutional ring chromosome 21, r(21), may potentially be predisposed to iAMP21 ALL.<ref name=":0" />

* Signs and symptoms - ~50% of cases are classified as high-risk based on an age of ≥10 years.<ref>{{Cite journal|last=Harrison|first=Christine J.|date=2015-02-26|title=Blood Spotlight on iAMP21 acute lymphoblastic leukemia (ALL), a high-risk pediatric disease|url=https://pubmed.ncbi.nlm.nih.gov/25608562|journal=Blood|volume=125|issue=9|pages=1383–1386|doi=10.1182/blood-2014-08-569228|issn=1528-0020|pmid=25608562}}</ref> Pediatric iAMP21 has been associated with a poor outcome. It displays an increased rate of relapse when treated on standard protocols. Further, the event-free survival and overall survival were significantly worse for individuals with the iAMP21 and standard-risk B-ALL, but not significant in individuals with iAMP21 and high-risk B-ALL.

* Laboratory findings - Low platelet count; Low WBC count (<50,000/μl)

* Bone Marrow and peripheral blood

* There are no unique morphological or cytochemical features that distinguish this entity from other types of ALL.<ref name=":02" />

* Cytogenetic morphology of the abnormal chromosome 21 can vary markedly between patients.<ref name=":1" />

* No detailed information is known, other than these cases occur exclusively in B-ALL.<ref name=":02" />